The BoE's rampant money printing and low interest rates since the last crash has bloated the housing and equities markets to the point where even a slight increase in the base rate could burst the bubble.
If the BoE tries to increase rates it may well crash the economy, if they don't it could lead to an inflationary spiral/cost of living crisis. Either way, disposable income/discretionary spending will be massively reduced. There's supposedly a tight labour market at the moment, so private sector wage rises may well be at/near the level of inflation. If the public sector doesn't keep up, will we see another summer/winter of discontent?
I don't think we're quite at the asset bubble levels of Tokyo '89 yet but we can't be that far off.